The WIHS is a multi-site prospective epidemiology cohort study of women enrolled in 1994 and 2002 who either are infected with HIV or are at increased risk for acquiring HIV infection. The purpose of the study is to continue follow-up of the WIHS cohort, thereby supporting studies of the natural and treated history of HIV infection in representative, primarily minority, adult women in the United States, as well as supporting studies of emerging questions related to long-term HIV infection and treatment. WIHS-IV scientific initiatives will include ongoing core research projects and the initiation of new projects on the predictors of response to antiretroviral therapy and long term consequences of HIV infection and HIV therapy in terms of cardiovascular disease, liver disease, hormonal function, neurocognitive impairment, cancer and other morbidities, as well as progression to AIDS and death. Additionally during the WIHS-IV grant cycle scientific collaborations will continue to expand independent, investigator-driven research grants. As an ongoing cohort study that, The Chicago site will continue to support the overall WIHS scientific research agenda by continuing to collect quality data and specimens from participants and maintain superb cohort retention. The Chicago site will also provide leadership for key areas of interest including HIV virology and host immunology, long term pathogenesis of HIV infection and treatment toxicities, and impact of viral resistance. Topics of study will include the effect of co-infections such as hepatitis C (HCV) and B virus (HBV), human papillomavirus (HPV); therapy use and treatment effects in women, behavioral and psychosocial factors influencing HIV disease, effects of metabolic abnormalities, impact of hormonal factors on HIV disease; the effects of aging and menopause on HIV disease, the interaction of environmental and host genetic factors on HIV disease; and the assessment of brain structure, neurocognitive functioning, and physical impairment among WIHS participants.